Localization and Glassy Dynamics Of Many-Body Quantum Systems

TL;DR

This paper provides numerical evidence that strongly interacting lattice bosons far from equilibrium can become trapped in long-lived, inhomogeneous metastable states, exhibiting glass-like slow dynamics and preventing thermalization.

Contribution

It demonstrates that quantum many-body systems can exhibit glassy dynamics and metastability, revealing a new aspect of non-equilibrium quantum behavior.

Findings

Long-lived inhomogeneous metastable states observed in simulations

Slowing down of density excitations above a threshold energy

Potential for experimental observation in cold atom systems

Abstract

When classical systems fail to explore their entire configurational space, intriguing macroscopic phenomena like aging and glass formation may emerge. Also closed quanto-mechanical systems may stop wandering freely around the whole Hilbert space, even if they are initially prepared into a macroscopically large combination of eigenstates. Here, we report numerical evidences that the dynamics of strongly interacting lattice bosons driven sufficiently far from equilibrium can be trapped into extremely long-lived inhomogeneous metastable states. The slowing down of incoherent density excitations above a threshold energy, much reminiscent of a dynamical arrest on the verge of a glass transition, is identified as the key feature of this phenomenon. We argue that the resulting long-lived inhomogeneities are responsible for the lack of thermalization observed in large systems. Such a rich phenomenology could be experimentally uncovered upon probing the out-of-equilibrium dynamics of conveniently prepared quantum states of trapped cold atoms which we hereby suggest.